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267 Cards in this Set
- Front
- Back
What is the purpose of the nasal passages? Whose law applies to this
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Filtration (primarily due to turbulence versus hairs actually filtering); humidification (to 100% relative humidity)
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What is the partial pressure of water vapor in the nasal passages at STP?
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47 torr
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What is the effect of humidification by the nasal passages on O2 delivery? Whose law applies here?
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Humidification decreases the driving pressure of O2 to the lungs- 100% FiO2 becomes diluted by the 47 torr of water vapor that is contributed by the nasal passages. Dalton's Law of Partial Pressures applies here
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How many ribs are there? How many true, fused. amd floating?
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12 ribs; 7 true, 3 fused at the sternum. 2 float
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The sternal angle (angle of Louis) is the landmark for _____. What is the significance of this?
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Landmark for 2nd rib (and 5th thoracic vertebrae)
landmark for carina; decompress pneumothorax at 2nd intercostal space, midclavicular line (below second rib) |
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70% of the work of breathing is accomplished by the ___________.
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Diaphragm
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_______% of the work of breathing is contributed by the diaphragm
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70%
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What is the function of the external intercostal muscles?
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Elevate the ribs and expand the AP diameter of the chest
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Diaphragmatic contraction causes________.
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Descent- moves down and increases the intrathoracic volume
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Descent of the diaphragm causes_________
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pressure in the chest to decrease, augments venous return
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Spontaneous respiration _______ venous return
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Increases/augments
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Internal intercostal muscles are used during ______
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expiration
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The diaphragm separates the ________ from the ______
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Thorax from the abdomen
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The _______ intercostals are the muscles of inspiration
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external
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The__________ intercostals are the muscles of expiration
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Internal
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The diaphragm has ____ major openings. What passes through each of them?
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Three openings: aortic, esophageal, and IVC foramen
Aortic: Aorta, thoracic duct, greater sphlanic nerves, and sometimes azygos vein Esophageal: Esophagus and Vagus nerve IVC foramen: Inferior Vena Cava, lymphatics, R. phrenic nerve |
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Movement of the ______ joint increases the AP diameter
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Costovertebral joint
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Movement of the costovertebral joint increases the ________
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AP diameter
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The upper ribs are elevated by the __________
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Diaphragm
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Elevation of the upper ribs causes ______ and _____ movement of the sternum
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Elevation and forward movement of the sternum
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The diaphragm is innervated by the _____ nerve, which is made up by CN_____
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Phrenic nerve, C3, 4, 5
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Each phrenic nerve controls _______
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innervation to 1/2 of the diaphragm independently; paralysis of 1 phrenic nerve does not effect the other 1/2 of the diaphragm
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The diaphragm is under _____ voluntary control
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limited
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When the diaphragm contracts, intrathoracic volume ______ and intrathoracic pressure ______, according to ______ law.
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Volume increases, pressure decreases according to Boyle's Law
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The lungs are attached to the _____ and the ______.
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Heart and trachea
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The lungs are attached to the heart and the trachea by the ______ and the ______.
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Pulmonary root and pulmonary ligament
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The right lung is _____, _____, and ______ than the left
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right heavier, shorter, wider than left
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The left upper and lower lobes are divided by the _______.
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Oblique Fissure
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The Right upper, middle, and lower lobes are divided by the _____ and _______.
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Oblique and horizontal fissures
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The pulmonary root is made up of _______.
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Blood vessels
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The pulmonary ligament is made up of ________
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An outcropping of the pleura
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What is the name of the "little tongue" on the LUL that would embryologically correllate the the middle lobe?
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Lingula
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What are the borders of the lungs/thoracic cavity at FRC at each of the following landmarks:
1. the midclavicular line 2. mid-axillary line 3. the spine |
MCL: xiphoid to 6th rib
Mid-axillary: 8th rib Spine: T10 |
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During deep inspiration, the lower borders of the lungs descend ________
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2 spaces
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What is the name of the artery that comes off of the subclavian that is sometimes used in cardiac surgery?
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Internal Mammary artery
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The internal mammary artery comes off of the ______
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Subclavian
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The pulmonary ______ carries deoxygenated blood from the RV
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Artery
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The pulmonary artery carries ________ blood
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Deoxygenated
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The left PA is attached to the aorta by the _______
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Ligamentum arteriosum
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How many pulmonary veins are there? How many pulmonary veins enter the heart?
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5 pulmonary veins; two joing before entering, so only 4 veins enter heart
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The pulmonary veins carry ______ blood from the lungs to the ______
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Oxygenated blood from lungs to LA
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________ arteries nourish bronchi, bronchioles, connective tissue of the lung, and pleura
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Bronchial arteries
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Lung tissue is supplied with oxygen and nutrients by _______
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the bronchial arteries
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The bronchial arteries arise from the _____
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Typically from the aorta
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Blood from the bronchial arteries is returned via ______
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Pulmonary vein
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Blood returning from the bronchial arteries via the pulmonary vein contributes to _________
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Venous admixture- the reason O2 saturation is never really 100%
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How is an anatomic shunt different from a physiologic shunt?
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Physiologic shunt is not pathalogic- created by venous admixture in a normal body
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Some bronchial veins join with pulmonary arteries, contributing to:
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Venous admixture
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The respiratory passages begin at the level of the ______ cartilage
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Cricoid
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What level is the cricoid cartilage? (C_____)
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C6
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Smooth muscle and glandular innervation of the airways is primarily ______ from the ______ nerve
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Parasympathetic; vagus nerve
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Pain fibers in the respiratory tract can arise from ________ and are carried by the ________
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mucous membranes, carried by vatus
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The vagus nerve supplies _______ and ______ within the respiratory tract
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Smooth muscle and glands
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The trachea is made up of _______ cells to lend _________
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Psuedostratified columnar epithelium; lends structure to airways
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Chronic irritation of the airways, such as smoking leads to increased _______ cells and decreased _______ cells.
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Increased goblet cells (mucous), decreased cilia (decreased ability to get rid of bacteria and debris)
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Columnar cells give way to _______ cells at the level of the ________
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Cuboidal epithelium at the level of the bronchi
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Cuboidal cells are very thin to allow for _____ and ______
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Diffusion and distensibility
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At the level of the respiratory bronchioles, the cell type changes from ________ to __________.
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Cuboidal to squamous cells
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At what level do cuboidal cells give way to squamous cells within the respiratory tract?
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The level of the respiratory bronchioles
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Squamous cells are:
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a single layer of very thin cells to allow for easy diffusion and gas exchange
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What are the major differences between the right and left mainstem bronchi?
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R: shorter (2.5 cm), wider, less acute angle
L: Longer (4.5 cm), narrower, more acute angle |
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Are the bronchi sensitive to pain?
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Relatively insensitive to pain, but sensitive to irritation
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Aspiration tends to go to the most ______ area. What is this when supine? When upright?
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Most dependent area; when supine, will go to RUL (most dependent area d/t sructure of R. mainstem bronchus); when upright, will go to RLL
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Each division of the trachea/bronchi is called a _________
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generation
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How many generations are there before the alveoli?
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20-25
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_______ within the airway starts to dissipate with successive generations
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Cartilage
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Succeeding generations increases the ________ and ________ of the airways
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number and cross-sectional area
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Flow velocity is _______ to area. Whose law?
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inversely proportional; Pouseille's Law
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Flow at the level of the respiratory bronchioles is almost exclusively by _______
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Diffusion
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Why does HFOV work?
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Difusion
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What is the relative velocity of flow at the level of the alveoli
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Very slow, due to large cross sectional area
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What are the three primary generations of bronchi?
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Main, lobar, segmental
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With succeeding generations, ______, ________, ________ all INCREASE
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number, cross-sectional area, muscular layer
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With successive generations, ______, _______, ___________, _______, ______ all DECREASE
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Flow velocity, cartilage, mucous cells, ciliated cells, and goblet cells all decrease
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Ciliated cells disappear by the _______ generation. What cell type appears here?
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6-7th generation; cuboidal cells also appear here
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The functional divisions of the airways are the _______, _______, and _______.
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Conductive airways, transitional airways, and respiratory airways
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What is the function of the conducting airways? What structures are involved?
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Conduct pasage of air; from trachea to respiratory bronchioles
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What is the function of the respiratory zone? What structures are involved? How many generations fall into this zone?
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Gas exchange; 8 generations; alveolar ducts, alveolar sacs, alveoli
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Structures of the conducting zone are _______ lined, and ______ gas exchange occurs here
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Mucosa lined; no gas exchange
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Structures of the respiratory zone are lined with_________ to allow for ________.
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Simple squamous epithelium; gas exchange occurs here
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_________ allow for gas exchange from one alveoli to another
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Pores of Kohn
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What structure accounts for the efficacy of the inspiratory pause technique?
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Pores of Kohn; allows time for gas to move through pores to re-inflate atelectatic areas
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Alveolar Type 1 cell: what is it and what does it do?
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Makes the structure of the alveolar wall; metabolically inactive, cannot replicate
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What cell type makes up the alveolar walls?
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Type 1 cells
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Alveolar Type 2 cells: what are they and what do they do?
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Make surfactant and continually secrete it by excocytosis; can turn into type 1 cells
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Alveolar Type 3 cells: what are they and what do they do?
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Macrophages
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What is the total surface area for gas exchange?
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70 m2
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How many alveoli does the average person have? When does number peak?
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300 million; peaks at age 9
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The parietal pleura is a serous membrane that lines the ______, ______, and ________.
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Mediastinum, diaphragm, and thoracic wall
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The lungs extend to the level of C______, which is above the level of the ___________
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C7, above the first rib
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The superior margin on the lung extending above the level of the first rib is significant for:
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Risk of pneumothorax with subclavian line placement or (infraclavicular) brachial plexus block
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Inspiratory muslecs (external intercostals) increase the ________ dimension of the chest, while the diaphragm increases __________
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External intercostals increase AP diameter, diaphragm increases vertical dimensions
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Boyle's law states that:
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Pressure and volume have an inverse relationship; if you increase the volume (space) within the thoracic cavity, you decrease the pressure
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The intrapulmonary or alveolar pressure is:
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about the same as atmospheric pressure
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The intapleural pressure is ______ at FRC, because:
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about -4 at FRC, because the lungs want to collapse and the ribs want to expand, creating a vacuum within the pleural space
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The transpulmonary pressure equals:
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Intrapulmonary pressure - intrapleural pressure
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__________ results because of increased transpulmonary pressure
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Negative pressure pulmonary edema
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Intrapleural pressure is always ______
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Always negative
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Compliance is defined as:
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Change in volume/ change in pressure
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What is the formula for static effective compliance?
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(TV)/(PP-PEEP)
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Normal adult lung compliance is about:
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200 mm Hg
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Lung compliance changes due to what three broad categories:
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Disease processes/pathology, lung volumes, and surface tension within the alveoli
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Emphysema causes _______ lung compliance; and is reflected by a _______ shift on the compliance curve
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Increased compliance: large floppy airways with poor recoil and poor gas exchange (upshift on compliance curve)
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Fibrosis causes _______ compliance, and is reflected by a _______ shift on the compliance curve
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Decreased compliance (not much volume change despite high pressures); downward shift on compliance curve
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Lungs have decreased compliance at ________ and _______ lung volumes
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Very low and very high
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Surfactant is produced by:
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Type II pneumocytes
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According to the law of laplace, the pressure required to keep alveoli open is directly proportional to__________, and inversely proportional to ________.
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Directly proportional to surface tension, inversely proportional to radius (size)
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Whose law describes the idea that if you have higher surface tension within the alveoli, more pressure will be required to keep them inflated?
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LaPlace
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Airflow resistance is _______ proportional to airway radius, according to ________Law
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resistance inversely proportional to radius; Pouseille's Law
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According to Pouseille's Law, airway resistance is inversely proportional to ________
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the radius to the 4th power
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Ohm's Law states that airway resistance =
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(Atmospheric pressure- alveolar pressure)/velocity
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The primary factor affecting whether flow is laminar or not is:_______
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Viscosity
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Reynold's number is directly proportional to _______, _______, ________ and inversely proportional to _________
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directly proportional to: Velocity, diameter, density; inversely proportional to viscosity
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A Reynold's number over _______ indicates turbulent flow
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4000; <2000=laminar flow
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________ promotes laminar flow, while ________, ________, ________ promote turbulent flow
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Viscosity promotes laminar flow, while velocity, increased diameter, and density promote turbulent flow
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Heliox is used in cases of increased airway resistance because
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It has a lower molecular weight (density) than oxygen and promotes laminar flow
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Resistance has a directly proprtional relationship with ______, _______, and _______
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length of tube, viscosity, and velocity all increase resistance
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Maximal voluntary ventilation is:
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The maximal amount of air that can be breathed in a given time (like maximal minute ventilation)
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The maximal amount of air that can be breathed in a given time :
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Maximal voluntary ventilation
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FVC:
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Maximal amount of air that can be exhaled following full inhalation
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Maximal amount of air that can be exhaled following full inhalation
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FVC
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FEV1
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Maximal amount of air that can be exhaled in the first second (Forced Expiratory Voume 1 second)
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If FEV1 and FVC are BOTH low, it is indicitive of:
|
Restrictive disease
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If FEV1/FVC is low, and FVC is normal, it is indicitive of:
|
Obstructive disease
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What is the advantage of the forced mid-expiratory flow rate?
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Effort independent
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Supine position _______
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Reduces FRC
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Induction of anesthesia reduces FRC by
|
an additional 15-20%
|
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What is the effect of muscle relaxants on FRC?
|
Decreases
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Approximately what % of TV is found within the conducting and transitional respiratory zones?
|
about 33%
|
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How is alveolar ventilation calculated?
|
Minute ventilation (TV x RR) - dead space ventilation
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Are the terms minute ventilation and alveolar ventilation interchangeable?
|
No; alveolar ventilation accounts for dead space ventilation
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Neck extension ________ (increases or decreases) dead space ventilation
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Increases (lenghthens conducting zone)
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An artificial airway (ETT) ________ (increases or decreases) dead space ventilation
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Decreases (due to smaller diameter, so smaller conducting zone)
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Positive pressure ventilation ________ (increases or decreases) dead space ventilation
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Increases; due to decreased VQ matching
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Hypotension ________ (increases or decreases) dead space ventilation
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Increases: areas are ventilated but not perfused
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Pulmonary embolism increases _________
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Increases dead space ventilation; areas are ventilated but not perfused
|
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Dead space (definition)
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ventilation which does not contribute to gas exchange (due to lack of perfusion)
|
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ventilation which does not contribute to gas exchange
|
Dead space
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Average Dead space ______ ml/kg or _______ ml
|
2ml/kg or 150 ml
|
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Anatomic dead space occurs because of the ________ zone
|
Conducting zone
|
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Alveoloar dead space:
|
Occurs because alveoli are ventilated but not perfused
|
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Physiologic dead space:
|
Alveolar + anatomic dead space
|
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VA =
|
VT-VD
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Shunt:
|
Perfusion but no ventilation (ex. atelectasis)
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Peripheral chemoreceptors sense:
|
Decreased O2, increased CO2, decreased pH
|
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Central Chemoreceptors sense:
|
Decreased pH, increased CO2
|
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What is the Hering-Breuer Reflex?
|
Stretch receptors in lungs send signals to brainstem to decrease respiration
|
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The primary respiratory center is located in the:
|
Medulla
|
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What does the Dorsal Respiratory Group do?
|
Contains inspiratory neurons that signal the lungs to breathe in (exhalation is passive); modulates the ventral respiratory group
|
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What does the Ventral respiratory Group do?
It is controlled by: |
Contains Inspiratory and expiratory neurons which are quiet during normal respiration; active during forced expiration and exercise; controlled by the Dorsal Respiratory Center
|
|
The Dorsal respiratory group contans:
|
Tractus solitarius- CN IX and X
|
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The apneustic center in the _______ signals a characteristic breathing pattern that looks like:
|
Pons; apneustic breathing = APRV type ventilation; large breathes with intermittent short exhalations (pontine breathing)
|
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What does the pneumotaxic center in the ______ do?
|
In Pons, Antagoizes the apneustic center, inhibits respiration
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J receptors: what are they and what do they do?
|
Juxtocapillary receptors within the lung respond to noxious stimuli (pulmonary edema, congestion, volatile anesthetics) and trigger an increased respiratory rate (rapid, shallow breathing)
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Volatile anesthetics produce the characteristic respiratory pattern by triggering _________ within the ______.
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Rapid, shallow breathing by triggering J-receptors within the alveolar interstitium
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J- receptors can be _______ or _______ receptors
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Stretch or chemoreceptors
|
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What is the afferent nerve that carries signals from the J-receptors in the alveolar interstitium?
|
Vagus (CNX)
|
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Respiration is triggered by ______ and ______ levels
|
CO2 and H+ ion levels
|
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Stretch receptors in the lungs carry signals via the ______ nerve to start/stop each respiratory cycle
|
Vagus
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Central chemoreceptors regulate ______ of the response to changes in CO2
|
80%
|
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________ chemoreceptors regulate 80% of response to changes in CO2
|
Central
|
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________ chemoreceptors respond to changes in CO2 more rapidly but have less of an overall effect than _________ chemoreceptors which respond more slowly but produce a more significant overall effect
|
Peripheral chemoreceptors faster, but only account for 20% of response, whereas central chemoreceptors are slower but produce 80% of the effect
|
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Central chemoreceptors are located in the ________
|
Medulla
|
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Central Chemoreceptors are triggered by ________ (but not _______ and _______)
|
Central chemoreceptors are only triggered by increased CO2 because it rapidly crosses the BBB whereas H+ and HCO3- are charged and cannot diffuse into the CSF to trigger these receptors
|
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Where are peripheral chemoreceptors located?
|
Aortic arch and carotid bodies
|
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Baroreceptors are located in the carotid and aortic _______ and chemoreceptors are located in the carotid and aortic_______
|
Baroreceptors = sinuses
Chemoreceptors = bodies |
|
_______ chemoreceptors are the bodies main response center for hypoxemia
|
Peripheral
|
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Which chemoreceptors are more sensitive: carotid or aortic?
|
Carotid
|
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Peripheral chemoreceptors respond to changes in:
|
CO2, pH, H+, O2
|
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Plasma PO2 less than ______ triggers peripheral chemoreceptors
|
<60
|
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The threshold CO2 that limits voluntary breath holding is:
|
CO2 50-70
|
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Capillary beds become very dense distal to ________ in the region of the ___________
|
pulmonary arterioles in the region of the respiratory bronchioles
|
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Pulmonary ___________ blood flow follows the divisions of the bronchi fairly closely whereas ________ blood flow does not
|
arterial blood flow follows bronchial divisons, venous return does not
|
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Bronchial arteries branch from the ________
|
Aorta
|
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Bronchial arteries meet the metabolic needs of:
|
the airways and pulmonary parenchyma
|
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The bronchial arterteries empty ________ blood into the pulmonary _______ for transport back to the heart
|
deoxygenated blood into pulmonary veins for return to LA
|
|
Average blood volume in the lungs: (ml)
|
450 ml
|
|
Large increases in the pulmonary blood volume (are/are not) well tolerated because of _______
|
Well tolerated because of compliance of pulmonary arterial system
|
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Pulmonary blood volume increases up to _________ are generally well tolerated
|
1L
|
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Total blood volume within the lungs generally equals about what % of CO?
|
9-10%
|
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Pulmonary vasculature generally has (larger or smaller) diameters than corresponding systemic vasculature?
|
Larger diameters, shorter branches, thinner membranes (Pouseille's law, Fick's Law)
|
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Pulmonary vasculature has less _____ and _____ than systemic arteries
|
Less smooth muscle and elastin
|
|
The biggest regulating factor on pulmonary blood flow:
|
Local factors (hypoxia)
|
|
Which has more control over pulmonary blood flow: local factors or autonomics?
|
Local factors
|
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Hypoxia within the lungs causes _______ and systemically causes _____.
|
Pulmonary: hypoxic pulmonary vasoconstriction
Systemic: vasodilation |
|
Hypercapnia and acidosis within the lungs causes _______ and systemically causes ________.
|
Pulmonary: mild vasoconstriction
Systemic: vasodilation |
|
Hypercapnia causes the bronchioles to:
|
dilate
|
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Slight changes in pulmonary vascular resistance have _______ effects because
|
large effects because it is such a low pressure system
|
|
Parasympathetic stimulation causes pulmonary vasculature to _______
|
Vasodilate
|
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Sympathetic alpha stimulation causes pulmonary vasculature to _______
|
Vasoconstrict
|
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Sympathetic beta stimulation stimulation causes pulmonary vasculature to _______ and causes bronchioles to ________
|
vasodilate and dilates bronchioles
|
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Which type of receptors are more prevalent within the lungs: alpha or beta?
|
Alpha
|
|
Sympathetic stimulation causes (vasodilation or vasoconstriction) because:
|
Relatively more vasoconstriction because alpha receptors are more numerous than beta receptors
|
|
Name 5 factors that cause vasoconstriction within the lung
|
1. Catecholamines
2. Angiotensin II 3. Histamine 4. PGF 2a 5. Endothelins |
|
Name 3 pulmonary vasodilators:
|
1. NO
2. PGE2 (prostaglandin) 3.PGI2 (prostacyclin) |
|
PGF2a = ?
Who should never receive this drug? |
Hemabate; never give an asthmatic hemabate because it causes pulmonary vasoconstriction
|
|
Endothelins cause _______ and ________.
|
Pulmonary vasoconstriction and platelet inhibition
|
|
What is the most important influence on pulmonary vasomotor tone?
|
Hypoxia
|
|
Acute and chronic hypoxia increases _______
|
Pulmonary vascular resistance
|
|
What is the benefit/intended effect of hypoxic pulmonary vasoconstriction?
|
VQ matching
|
|
What are normal pulmonary SBP, DBP, and MAP?
|
25/8, mean 15
|
|
PAP = _______
|
RV pressure, but diastolic is higher d/t pulmonic valve
|
|
Pulmonary capillary pressure:
|
7 torr
|
|
Pulmonary capillary wedge pressure estimates _________, but overestimates it by _________.
|
PCWP = LVDP but overestimates by 2-3 torr
|
|
Pulmonary lymphatics begin in connective tissue surrounding ________
|
Terminal bronchioles
|
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Lymphatics course to the _______ and then primarily empty into ________
|
Course to the hilum and primarily drain into the right lymphatic duct
|
|
Lymphatics remove _______ and _____ that enter the alveoli
|
Particulate matter and protein
|
|
What effect does chronic congestion/pulmonary edema have on lymphatics?
|
Increase capacity
|
|
Residual volume: definition and average volume
|
Air remaining in lungs following maximal exhalation; cannot be voluntarily removed from lungs; 1200ml
|
|
Expiratory reserve volume: definition and volume
|
Maximal amount of air that can be expired from normal end expiration; 1100 ml
|
|
Average TV
|
500 ml
|
|
Inspiratory reserve volume: definition and volume
|
Maximal amount of air that can be inhaled following normal inhalation; 3000 ml
|
|
Inspiratory capacity =
|
IC = TV + IRV; 3500 ml
Maximal inhalation from normal expiratory level |
|
Vital capacity =
|
VC = IRV + VT + ERV; 4500 ml
Maximal amount of air expired from maximal inhalation |
|
FRC =
|
Volume of air remaining in lungs at end expiration; FRC= RV + ERV; 2300 ml
|
|
TLC =
|
5800 ml; volume of air in lungs at maximal inhalation; RV + ERV + TV +IRV
|
|
Name 5 conditions/factors that increase the closing volume:
|
Pregnancy, obesity, COPD, CHF, aging, supine positioning
|
|
Increased closing volume leads to pulmonary _______
|
shunting
|
|
Respiratory quotient:
|
0.8; ratio of CO2 produced to O2 consumed
|
|
Pulmonary vascular resistance = (1/?) of systemic
|
1/8
|
|
Ventilation and perfusion are greatest in zone ____
|
3
|
|
Zone 1: relationship between Pa, PA, and PV
|
PA>Pa>Pv
|
|
Zone 2: relationship between Pa, PA, and PV
|
Pa>pA>Pv
|
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Zone 3: relationship between Pa, PA, and PV
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Pa>Pv>PA
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|
Where should the tip of a PA catheter lie?
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Dependent portion of the lung (zone 3) where both arterial and venous pressure are greater than alveolar pressure and there is continuous blood flow leading to the left heart
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|
What factors tend to hold fluid in the pulmonary capillaries? Which factors encourage movement into the interstitium?
|
Plasma colloid oncotic pressure holds fluid within the capillaries; interstitial colloid osmotic pressure, capillary hydrostatic pressure, and negative interstitial fluid pressure encourage fluid movement into interstitium
|
|
Under normal circumstances, the net of forces favors movement of fluid:
|
into the interstitium
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|
Which does pulmonary edema affect more: O2 or CO2?
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O2; CO2 is 20 times more diffusible
|
|
Pulmonary edema can be caused by any factor that:
|
Any factor that increases pulmonary interstital pressure into positive range
|
|
Pulmonary edema will not occur until pulmonary interstital pressure exceeds
|
Plasma colloid oncotic pressure (28 torr)
|
|
______ % of blood flow goes to R. lung and ______% to L. lung
|
55% Right, 45% left
|
|
Dependent alveoli are the _______ compliant and receive the ________ blood flow
|
Most compliant and best perfused
|
|
zone 1: _______like
|
Dead space like
|
|
Zone where capillary flow is variable with respiration
|
Zone 2
|
|
Zone where capillary flow is continuous
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Zone 3
|
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Zone 3: ______ like
|
Shunt like- continuous blood flow, but could have decreased ventilation
|
|
Why is lateral position worse than supine from a pulmonary standpoint?
|
Abdominal contents compress the dependent lung which would otherwise have the best VQ characteristics
|
|
What effect does PEEP have on pulmonary dynamics?
|
Expands zone 1 (increases alveolar size such that PA may be >Pa)
|
|
VQ matching is 1:1 at about the level of __________
|
the third rib
|
|
Treatment for negative pressure pulmonary edema
|
Correct underlying cause, administer O2/CPAP, intubation/ventilation w/PEEP as necessary to support oxygenation; consider steroids to stabilize pulmonary capillary membranes; support hemodynamics (morphine/nitroglycerin to decrease preload and inotropes to promote forward flow)
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|
_________ and ________ are a cause of normal physiologic shunting and venous admixture
|
Bronchopulmonary anastomoses and thebesian veins
|
|
General anesthesia results in a ________% shunt, due to:
|
10% shunt d/t supine positioning, positive pressure ventilation (more even distribution of flow/decreased VQ matching), decreased CO (especially with PEEP), and atelectasis
|
|
________ decrease hypoxic pulmonary vasoconstriction and _______ do not
|
volatile anesthetics decrease effectiveness of Hypoxic pulmonary vasoconstriction; IV anesthetics do not
|
|
Although general anesthetics _______ chest wall compliance, they ________ FRC which leads to an overall _________ in compliance
|
Increase chest wall compliance, but decrease FRC which leads to an overall decrease in compliance under GA
|
|
Volatile anesthetics decrease the ventilatory response to _______, _______. and _______
|
CO2, acidosis, and hypoxia
|
|
Blood spends approximately _______ seconds in the pulmonary system, with _______ in the pulmonary capillaries, but it only needs approx ________ seconds for gas exhchange
|
spends 4-5 seconds in system, 0.75 in capillaries, but only needs 0.25 seconds for gas exchange under normal conditions
|
|
CO2 is _______x more diffusible than O22
|
20x
|
|
One lung ventilation causes _______ through non-dependent lung
|
Shunt through non-dependent lung
|
|
The solubility coefficient for O2 in plasma:
CO2: |
O2 0.003 ml/dl
CO2: 0.06 ml/dl |
|
How much O2 is bound to each Hgb molecule?
|
1.36ml/ g Hgb/100ml
|
|
What layers must O2 diffuse through to get out of alveolus and into blood?
|
1.Alveolar fluid layer (with surfactant)
2. Simple squamous epithelium 3. Epithelial basement membrane 4. Interstitial space 5. capillary basement membrane 6. capillary endothelial membrane |
|
The total surface area of the respiratory membrane is:
|
50-100m2
|
|
Total volume of blood in pulmonary capillaries is:
|
60-140 ml
|
|
Dalton's Law:
|
Law of partial pressures; each gas in a mixture exerts its own pressure proportional to it concentration in the mixture
|
|
Pressure of gas in a solution is determined by its _________. The less dissolved, the _________
|
Solubility coefficient; less soluble = less dissolved in solution = higher pressure
|
|
Solubility of gas in a liquid is described by ________ Law.
|
Henry's Law
|
|
An example of Henry's Law:
|
Bubbles in a soda can
|
|
Concentration of a dissolved gas in solution = ________ x _________
|
Pressure x solubility coefficient
|
|
Fick's Law:
|
Diffusion is proportional to pressure gradient across membrane/ concentration gradient, surface area of the membrane, and diffusion coefficient (calculation includes molecular weight), and inversely proportional to membrane thickness
|
|
Diffusion capacity:
|
Volume of gas that diffuses through membrane each minute per each pressure difference of 1mm Hg
|
|
Normal diffusion capacity for O2:
|
231 ml/minute
|
|
How can the body increase diffusion capacity?
|
1. Opens dormant pulmonary capillaries (increases surface area)
2. Better VQ matching |
|
How does negative pressure pulmonary edema happen?
|
Laryngospasm or occluded ETT + large inhalation generates extremely negative intratoracic pressure which pulls fluid from the pulmonary capillaries
|
|
The dorsal and ventral respiratory groups, along with projections of CN _____ and _______ are located within the
|
Tractus solitarius
|
|
Pulmonary embolism causes ________ breathing, wherease pulmonary vascular congestion causes _________
|
PE: Rapid, shallow breathing
Pulmonary vascular congestion = hyperpnea |
|
The trachea extends from C_______ to T_______
|
C6-T4/5
|
|
Average adult minute ventilation:
|
5L
|